Issue 324: fix set_mipmap_image
Issue 324: fix set_mipmap_image

mammadori/pyglet,mammadori/pyglet,theblacklion/pyglet,oktayacikalin/pyglet,mammadori/pyglet,oktayacikalin/pyglet,oktayacikalin/pyglet,theblacklion/pyglet,theblacklion/pyglet,mammadori/pyglet,theblacklion/pyglet,oktayacikalin/pyglet,oktayacikalin/pyglet,theblacklion/pyglet